update nix-shell sources; GitHub Actions for nix-shell (#1002)

* update `nix-shell` sources; use `niv`

* nix readme update

* don't use `niv`

Author: peterbecich

.github/workflows/nix-shell.yml

@@ -0,0 +1,19 @@
+# https://nix.dev/tutorials/continuous-integration-github-actions
+name: "Test nix-shell"
+on:
+  push:
+    branches:
+    - '**'
+    paths-ignore: []
+  pull_request:
+    paths-ignore: []
+
+jobs:
+  nix-shell:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/[email protected]
+    - uses: cachix/install-nix-action@v16
+      with:
+        nix_path: nixpkgs=channel:nixos-21.11
+    - run: nix-shell --pure --run "cabal update && cabal build all --enable-tests"

README.md

@@ -2,6 +2,7 @@
 
 [![Build Status](https://travis-ci.org/haskell/hackage-server.png?branch=master)](https://travis-ci.org/haskell/hackage-server)
 [![Build status](https://github.com/haskell/hackage-server/actions/workflows/ci.yml/badge.svg)](https://github.com/haskell/hackage-server/actions/workflows/ci.yml)
+[![Build status](https://github.com/haskell/hackage-server/actions/workflows/nix-shell.yml/badge.svg)](https://github.com/haskell/hackage-server/actions/workflows/nix-shell.yml)
 
 This is the `hackage-server` code. This is what powers <http://hackage.haskell.org>, and many other private hackage instances. The `master` branch is suitable for general usage. Specific policy and documentation for the central hackage instance exists in the `central-server` branch.
 
@@ -14,14 +15,16 @@ of libraries that provide Unicode and Globalization support.
 The [text-icu](https://hackage.haskell.org/package/text-icu) Haskell package
 uses the [icu4c](http://icu-project.org/apiref/icu4c/) library to build.
 
-### Nix shell
+### [`nix-shell`](https://nixos.org/manual/nix/stable/command-ref/nix-shell.html)
 
-If you have the Nix package manager installed, the easiest way to obtain
-`hackage-server`'s dependencies is using the Nix shell:
+If you have the [Nix package manager](https://nixos.org/) installed, the easiest way to run `hackage-server` is by using the `nix-shell`. It should be unnecessary to install any dependencies manually. In this repository:
 
-    nix-shell
+    nix-shell --pure
 
-Note: `libbrotli-dev` has to be installed manually.
+    [nix-shell]$ cabal v2-run -- hackage-server init
+
+    [nix-shell]$ cabal v2-run -- hackage-server run --static-dir=datafiles/ --base-uri=http://127.0.0.1:8080
+    hackage-server: Ready! Point your browser at http://127.0.0.1:8080
 
 ### Manually
 

shell.nix

@@ -1,22 +1,26 @@
 let
   nixpkgs = builtins.fetchTarball {
-    # master on 2021-08-02
-    url = "https://github.com/NixOS/nixpkgs/archive/70e001f35cc363eb789ea0a04eff11b86c440ba3.tar.gz";
-    sha256 = "1mrhbcfa8kkx1qnax8xh41grinqiycl56wlws5vvrli8w0pzgl1r";
+    # master on 2022-05-14
+    url = "https://github.com/NixOS/nixpkgs/archive/1d370bd07399fb52cea6badfbffbc90ac9b0f8f0.tar.gz";
+    sha256 = "1ln4vwy185gwhbf4f8vanrlj4w4bhwrcsb2m8fnm99f4zqzvp7fs";
   };
 
   pkgs = import nixpkgs { config = { }; };
 
 in
 pkgs.mkShell {
-  buildInputs = [
+  buildInputs = with pkgs; [
     # Haskell development
-    pkgs.cabal-install
-    pkgs.ghc
+    cabal-install
+    ghc
 
     # Dependencies
-    pkgs.icu
-    pkgs.zlib
-    pkgs.brotli
+    glibc
+    icu67
+    zlib
+    openssl
+    cryptodev
+    pkg-config
+    brotli
   ];
 }